(1) Field of the Invention
This invention relates to a disposable manipulative laboratory device for transferring biological fluids from at least one primary container to an associated secondary container. The invention is disclosed for general utility under laboratory conditions and is illustrated, in a preferred embodiment, for decanting serum, or plasma, from red cells in whole blood after they have been separated, as by centrifugation.
The invention further includes combinations which allow for gang transfer of a number of samples by one operator into a plurality of associated secondary containers, through rack constructions and an air pump which accurately transfers controlled volumes of biological fluid from each of a plurality of compartments in a disposable enclosure.
(2) Background of the Invention
The transfer of biological fluids under laboratory conditions is a necessary operation performed on a large scale in even relatively small laboratories. For example, when blood specimens are tested in clinical laboratories, it is frequently necessary to obtain a sample of the blood serum or plasma after the serum has been separated from the suspended cellular material. The serum or plasma which remains in the top portion of a blood collection-type tube after centrifugation must be quickly removed for further clinical testing. Usually, each blood collection tube is individually handled, in a laborious manual operation, with the concommitant danger that the serum will come in contact with the skin of laboratory personnel. This contact presents serious health risks to the laboratory personnel, among which the risk of hepatitis is perhaps the most serious. The present device allows for a transfer of biological fluids, such as separated blood serum or plasma, without exposing the serum to the air or the operating person as it is being transferred.
Among prior art devices concerned broadly with transfer of biological fluids, such as serum, from a primary container to a secondary container for analysis work, are the United States Patents, as follows:
Natelson -- u.s. pat. No. 3,951,605 PA1 Atwood -- u.s. pat. No. 3,948,607 PA1 Forsstrom -- u.s. pat. No. 3,945,412 PA1 Lanier -- u.s. pat. No. 3,938,958 PA1 Beall -- u.s. pat. No. 3,907,505 PA1 Lemieux -- u.s. pat. No. 3,902,852 PA1 LeBLANC -- U.S. Pat. No. 3,871,832 PA1 Haug -- u.s. pat. No. 3,869,252 PA1 Ohringer -- u.s. pat. No. 3,846,077 PA1 Tocci -- u.s. pat. No. 3,833,341 PA1 Johnson -- u.s. pat. No. 3,826,621 PA1 Sendra -- u.s. pat. No. 3,802,844 PA1 Zauft -- u.s. pat. No. 3,796,544 PA1 Blechman -- u.s. pat. No. 3,751,990 PA1 Hamilton -- u.s. pat. No. 3,582,285 PA1 Nejame -- u.s. pat. No. 3,580,301 PA1 Sequeira -- u.s. pat. No. 3,551,112 PA1 Sanderson -- u.s. pat. No. 3,522,011 PA1 Jones -- u.s. pat. No. 3,511,613 PA1 Baruch -- u.s. pat. No. 3,193,359 PA1 Clevenger -- u.s. pat. No. 2,644,743 PA1 Cheney -- u.s. pat. No. 1,606,400 PA1 Keller -- u.s. pat. No. 768,605
Significantly, the various and sundry apparatus taught by these prior art references do not include a disposable device which may be attached to the open upper end of a primary container which is then pivoted so that biological fluid may transfer through an outlet means which is operable to ensure that only a controlled volume of fluid will enter an associated secondary container.
The broad concept of a pivoting rack for decanting biological fluid is known, as shown by various of these references, e.g., the patents to Clevenger, Keller or Cheney. Unlike these racks which allow for a simple decanting operation of a gang of primary containers, the present invention is significantly characterized by a disposable manipulative transfer device that cooperates with at least one primary container to transfer fluid therefrom.
The patents to Lanier and Tocci illustrate pivoting devices for aligning a plurality of samples over a receiving plate. Lemieux uses a plurality of syringes capable of withdrawing small quantities of liquid and spotting them on a plate for microanalysis. In Tocci, a plurality of nozzles are held against a chromatographic plate that is heated in order to evaporate the solvent in deposited samples. As such, Lemieux and Tocci are directed to chromatography, per se, and not with large scale serum transfer.
The patents to Forsstrom, Blechman and Nejame illustrate rotating test tube racks, wherein a single module is indexed over various stations for a plurality of rotating tubes. As such, these patents illustrate indexing of test tubes under stationary nozzle means, and are not concerned particularly with an apparatus as disclosed herein wherein a simultaneous transfer of biological fluids may be accomplished from a plurality of primary containers to a plurality of secondary containers.
Various other forms of automated apparatus for transferring liquid from a source to a container are illustrated by these patents. The patents to Zauft and Haug employ electronically controlled nozzles which are positioned over a plurality of test tubes being conveyed past a dispensing station. Both of these patents illustrate completely automated testing devices, and not a disposable liquid laboratory device for transferring biological fluids from at least one primary container to an associated secondary container. The patents to Natelson, Sanderson and Baruch further illustrate entire analytical processes wherein a plurality of containers are transported along a conveyor device and past a stationary sample injection station. These patents also do not represent a disposable transfer device for biological fluids, but rather illustrate instruments which are capable of operating upon serum transfers after they have been assembled into a plurality of secondary containers. As such, these patents illustrate end uses for biological samples which have been previously transferred by the present invention.
The patents to Atwood and Johnson illustrate automated transfer systems wherein liquid is transferred from one container to another. The patent to Atwood employs hydraulically actuated pumps for drawing in slugs of samples from a probe device. The automated device of Johnson is specifically concerned with transferring liquids between containers, though his apparatus constitutes a hydraulic pumping system, and not a disposable manipulative laboratory device for transferring biological fluids as is presented herein. Clearly, none of the above-discussed patents disclose a simple manipulative device for decanting and transferring a series of biological fluids from primary containers, nor one both disposable and mountable directly upon the primary containers. The patents to Beall and Hamilton are cited merely to illustrate plastic receiving packages, wherein the packages themselves are indicated to be disposable. The patents to Sendra, Jones and LeBlanc illustrate various known forms of test tube holding devices, and are pertinent only insofar as they represent the practice in the art to support a plurality of test tubes in a holder. The patent to Ohringer illustrates a liquid sample collection tube which may be employed as the primary container according to the present invention. Ohringer further teaches a transfer tube for collecting serum alone, and this transfer tube may also be a primary container contemplated by teachings of the present invention. Finally, the patent to Lanier illustrates another disposable laboratory device containing one or more compressible tubes, which are filled by a peristaltic pumping action. As such, Lanier is merely only of interest and illustrative of the state of the prior art.
In summary, while the broad concept of a plurality of pivotable primary containers for decanting into a plurality of aligned secondary containers is known, none of these patents, individually or collectively, teach the specific structure of a disposable biological fluid transfer device which is characterized by being mounted proximate the pouring end of one or more primary containers, to define a closed transfer passage for fluids that are transferred at controlled rates and volumes past a valved outlet by a means for delivering an applied source of pressurized gas.